Update XML element with LINQ to XML in VB.NET
- by Bayonian
Hi,
I'm trying to update an element in the XML document below:
Here's the code:
Dim xmldoc As XDocument = XDocument.Load(theXMLSource1)
Dim ql As XElement = (From ls In xmldoc.Elements("LabService") _
Where CType(ls.Element("ServiceType"), String).Equals("Scan") _
Select ls.Element("Price")).FirstOrDefault
ql.SetValue("23")
xmldoc.Save(theXMLSource1)
Here's the XML file:
<?xml version="1.0" encoding="utf-8"?>
<!--Test XML with LINQ to XML-->
<LabSerivceInfo>
<LabService>
<ServiceType>Copy</ServiceType>
<Price>1</Price>
</LabService>
<LabService>
<ServiceType>PrintBlackAndWhite</ServiceType>
<Price>2</Price>
</LabService>
</LabSerivceInfo>
But, I got this error message:
Object reference not set to an instance of an object.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Error line:ql.SetValue("23")
Can you show me what the problem is? Thank you.
